2.2. Selection of sites
A household survey was conducted on 132 local farmers in February
2014 to obtain baseline information about agricultural practices and identify potential sampling sites. This work was conducted using as a reference the baseline household survey carried out at the Makueni/ Wote site in 2012 (Mwangangi et al., 2012). The aim of that work was to gather information on household composition, farming systems, di- versity in farming activities, and characterize agricultural production systems and land uses. Moreover, group discussions were also held with extension and livestock officers from the Ministry of Agriculture, local administration and farmer self-help groups. Informed verbal con- sent was obtained from every household prior to the survey. In the end, three main land uses were selected with sites being classified as: (i) croplands having soil water conservation (SWC) structures, (ii) crop- lands not having SWC structures (conventional agriculture), and (iii) semi-natural vegetation. All selected sites occurred on arenosols, including those hosting semi-natural vegetation. Specific agricultural sites were selected because they were cultivated for over 40 years. Moreover, those having SWC structures had them established for at least 30 years (Table A1). The survey also confirmed that the use of min- eral fertilizer across different farms was nonexistent, which minimized the potential confounding effects posed by its differential use between the different farms. Ultimately, 14 sites implementing soil and water conservation measures were selected and classified according to specific cultivation practices (i.e. woody species planted in trenches
‘Fanya-Tree’ (n = 9) or herbaceous crops planted in trenches ‘Fanya-
Grass’ (n = 5)). Additionally, 10 sites implementing conventional agri- culture, and 10 sites hosting native vegetation, being in direct vicinity of the sites with SWC measures, were also selected to serve as reference land uses.